Conrad sciiraube and carl schmidt



NlTED as CONRAD SCHRAUBE AND CARL SCHMIDT, OF LUDVVIGSHAFEN, GERMANY,ASSIGNORS TO THE BADISCHE ANILIN AND SODA FABRiK, OF SAME PLACE.

NITROSANHN COMPOUND.

SPECIFICATION forming part of Letters Patent No. 531,976, dated January1, 1 895. indication filed y 11894. Serial No. 519,026. (Specimens)Patented in France November 13, 1893.1?0- 234,029.

To all whom it may concern.-

Be it known that we, CONRAD SGHRAUBE and CARL SCHMIDT, doctors ofphilos0phy,subjects of the King of Prussia, German Emperor, residing atLudwigshafen-on-the-Rhine, in the Kingdom of Bavaria and Empire ofGermany, have invented new and useful improvements in the Manufacture ofa New Nitrosamin Compound Derived from Naphthylamin, (for which patentshave been obtained in France, dated November 13, 1893, No. 234,029,certificate daddition of February 5, 1894, and June 11, 1894,) of whichthe following is a specification.

In the production of certain shades of color by means of one well-knownprocess the dyer combines diazo compounds with amins or phenols on or inthe presence of the fiber itself. Now since the diam-compounds generallyare an extremely unstable class of bodies, it is necessary that theyshould be prepared in the dyeing factory as they cannot practically betransported. The preparation of the diam-compounds for the purpose inquestion is frequently an inconvenient or difficult matter as the bestresult can only be attained by careful and accurate observance ofcertain narrowly bounded conditions. Moreover the conditions which arebest for obtaining the diazo-coinpounds sometimes yield these bodiesadmixed with acids and salts in such quantity that the product is notwell suited for use in the dyeing process mentioned.

o have discovered that on treating diazocompounds such as arehereinafter more particularly defined with caustic alkalies they areconverted ultimately into the alkali-salts of theisomeric nitrosaminswhich compounds can easily be isolated and possess considerablestability. These constitute a new class of compounds and arecharacterized by the following generic propertiesz-They are soluble inwater, giving a somewhat alkaline solution and yield practically no dyein aqueous solution with a solution of naphthol in an excess of alkali.By treatment with the equivalent proportion of an acid these alkalisaltsare converted in some cases into the free nitrosamin which is lessstable than the alkali salt but can in some cases if desired be preparedin the solid state and used in the form of paste. On treatment with alarger proportion of acid preferably in the presence of a little nitrousacid, the bodies of this new class are smoothly and readily reconvertedinto the corresponding diazo compounds. Thus by the aid of our inventionit is possible to prepare stable compounds capable of transport whichcan easily be converted into diazo-compounds ready for use in theaforepurpose the nitrosamin in the form of salt is mixed withhetanaphthol or other suitable component and this mixture is printed onthe fiber and the color developed by means of a weak acid such as aceticacid or the carbonic acid of the atmosphere. application constitutes theprincipal use of our new nitrosamins.

The processes above described for the production of our new nitrosaminscan be applied to a large variety of diam-compounds. The conversion intonitrosamin is most easil y effected in the case of the diam-compoundswhich contain one or more acid substituting groups such as nitro-groups,or two or more halogens and the like. diam-compounds from thenitro-auilins, dichloro-anilin, nitro-benzidin and the like can beconverted into the corresponding nitrosamins of the new class bytreatment with In some cases this Thus for instance the So caustic sodaat the ordinary temperature.

On the other hand the diam-compounds from anilin, toluidin,naphthylamin, benzidin and the like which contain no acid substitutinggroups must be heated with strong alkalies at the temperature of thewater-bath or higher in order to effect the desired conversion. Betweenthese two extreme groups of diazo-compounds there are ranked sultoacidsand all such diam-compounds as contain on the whole less strongly acidsubstituting groups than those first mentioned such for instance as thediazo-compounds from. the sulfanilic acid, para-brom-anilin and thelike, and these can be converted into nitrosamins of the new class bytreatment with caustic alkali at .a temperature intermediate to thatpreferably employed when using diam-compounds belong- ,ing to theextreme groups previously referred to.

h We have discovered that speaking generally the temperature requiredfor the conver sion of diazo-compounds into our new nitro' samincompounds varies according to the acidity of the substituting groups;the conversion being the more readily effected the more strongly acid'an'effect these are capable of producing under the circumstances of thereaction.

By this specification we do not intend to claim generally thenitrosamins resulting from the treatment of the diam-compoundsherein-defined with caustic alkaliesbut to claim the specific nitrosaminderived from naphthylamin.

The following example will serveto illustrate the manner in which ourinvention can best be carried intopractical effect and our newnitrosamin obtained from naphthylamin.

Example-Mix about two. (2) parts by weight of diazo-naphthalene-chloridsolution, containing about ten to twelve per cent.

I to 12%) thereof, with about one (1) part of per cent. NaOH.

caustic soda lye containing about thirty-five Stir continuously and asthe diazo-solution runs in, add one part of powdered caustic soda. Keepthe temperature below plus five degrees centigrade (+5 0.) during thewhole time of rniz-- h ing. In the meantime prepare a hot solution ofabout one (1) part of caustic soda in one (1) part of caustic soda lyecontaining about thirty-five per cent. (35%) NaOH at about one hundredand fifty degrees centigrade (150 0.), and at this temperature run ingradually the diazo-mixture obtained as above described. Stir wellduring this operation and gradually add one (1) part more of causticsoda so that the boiling point of the mixture shall admit of thetemperature being maintained at about one hundred and forty to onehundred and fifty degrees centi-. grade (140 to 150 0.). \Vhen nounchanged diazo-compound is present in the melt, allow it to cool toabout ninety to one hundred degrees centigrade to 0.). This point can beascertained by testing a diluted sample of the melt with sodiumbeta-naphtholate.

Dilute the melt with hot water, adding enough to renderit easy tocollect the nitrosamin by filtration and then filter hot. To purify thecrude compound so obtained dissolve in water, filter and reprecipitatethe nitrosamin with strong caustic soda solution. The nitrosamin is inthe form of sodiumsalt.

The diazo-naphthalene-chloride used in the above example may be preparedin any wellknown way from either alphaor beta-naphthylamin.

Our new naphthyl-nitrosarnin possesses all the generic properties of thenew class of nitrosamins hereinbefore mentioned and occurs as ayellowish powder or paste soluble in water, giving an alkaline solutionand is further characterized by yielding red shades when brought on thefiber together with sodium beta-naphtholate and subsequently eX- posedto the action of the air. These shades of red are slightly more or lessbluish accord ingly as the nitrosamin is prepared from alpha or betadiam-naphthalene respectively. On treatment with an excess of acidparticularly in the presence of a trace of nitrous acid it isconvertedinto diam-naphthalene.

Now, what we claim isp The new nitrosamin which can be derived fromdiam-naphthalene which occursas a

